NO LINK has been found between oral antibiotic use in adults and increased risk for early-onset colorectal cancer, according to a new study. The incidence of early-onset colorectal cancer (CRC) has risen over the past three decades. Despite this increase, the factors driving this trend remain unclear. Given the increased use of antibiotics and their impact on the gut microbiome, researchers have questioned whether antibiotic use might contribute to early-onset CRC.
The study aimed to investigate this association with a population-based, nested case-control study conducted at Kaiser Permanente in Northern California, USA. Researchers identified 1,359 early-onset CRC cases between January 1998–December 2020, matching them with 4,711 controls correlated by age, sex, race and ethnicity, primary care facility, and duration of drug benefits using incidence density sampling. The mean age of participants was 44.3 years, with 47% being female. Antibiotic exposures, confounders, and outcomes were determined through electronic databases. Statistical analyses included both unadjusted and adjusted models to evaluate the relationship between antibiotic use and early-onset CRC risk.
“We found no convincing evidence to establish a link between oral antibiotic use and early-onset colorectal cancer,” said lead researcher Jeffrey K. Lee.
In both unadjusted (odds ratio [OR]=1.09; 95% CI: 0.94–1.26) and adjusted models (adjusted OR=1.04; 95% CI: 0.90–1.22), there was no significant association between antibiotic use and early-onset CRC risk. Additionally, no notable associations were observed when examining antibiotic use by coverage spectrum, bacterial target, antibiotic class, or total antibiotic dispensations. However, an increased risk was noted for patients with more than 120 cumulative days of antibiotic use compared to those with no antibiotic use (adjusted OR=1.54; 95% CI: 1.15–2.06).
The study concluded that there is no compelling evidence to support a link between oral antibiotic use in adults and early-onset CRC. Nonetheless, the observed risk associated with prolonged antibiotic use warrants further investigation. “Patients should be reassured that antibiotics are safe, at least during early adulthood, and does not increase your risk of early-onset colorectal cancer,” Lee said. “However, antibiotic stewardship is critical to protect patients from harms caused by unnecessary antibiotic use and help combat antibiotic resistance.”
Reference
Lee JK et al. Association of oral antibiotics and risk of early-onset colorectal cancer. Digestive Disease Week, 18-21 May, 2024.
